Effect of Macrolide Treatment on a Novel Pathway of Neutrophilic Inflammation in

描述(由申请人提供)： 我们描述了一种新的信号通路，信号转导中性粒细胞(PMN)进入并损害呼吸道，这可能在慢性阻塞性肺疾病(COPD)中发挥作用。胶原蛋白的化学或酶促分解会释放一种三肽，PGP和一种乙酰化形式(N-？-PGP)，它们对PMN具有趋化作用。长时间吸入这种多肽会导致肺泡扩大和右室肥厚。此外，在雾化内毒素(LPS)暴露的动物的呼吸道中发现了PGP，并显著促进了PMN的内流。PGP的酶促合成是一个分步过程，最初涉及基质金属蛋白酶(MMP8)和(或)MMP9和丝氨酸蛋白酶(PE)催化最后的反应。我们还发现，Pgp存在于大多数COPD患者的支气管肺泡灌洗液(BALF)和/或痰中，但不存在于对照组或哮喘患者中。来自COPD患者而非对照组的痰也含有从纯化的胶原体外产生Pgp所需的所有酶机制，这种Pgp的产生可以被基质金属蛋白酶-8或基质金属蛋白酶-9抑制剂或PE特异性抑制剂所阻断。目前由COPD临床研究网络(CRN)进行的大环内酯类试验为研究PGP在COPD的呼吸道炎症中的作用提供了一个独特的机会。在这项试验中招募的COPD患者队列中Pgp和N-？-Pgp的测量将提供只有通过另一项大规模临床试验才能获得的信息。这项试验目前的登记期限提供了一个重要的机会之窗，掩盖了这项提议的时间敏感性。检测痰中基质金属蛋白酶和肺泡刺激素的水平和活性将为慢性阻塞性肺疾病中PGP的产生提供新的重要信息，并寻找可能的新的治疗靶点来对抗这种疾病的呼吸道炎症。重要的是，大环内酯类抗生素已被确定为MMPs的负转录调节因子。这被认为是一种可能的治疗慢性肺病(如COPD)的活性。最后，这项试验将使我们能够在服用阿奇霉素和对照组的大量COPD患者队列中检验这一假说，从而为大环内酯类药物在COPD中的活性提供科学依据。我们的基本假设是，服用阿奇霉素的COPD患者的N-？-Pgp/Pgp水平和产生N-？-Pgp/Pgp的酶的活性，特别是MMPs和PE，低于服用安慰剂的COPD患者，这种降低将与这些患者临床终点的改善相关。具体目的：1.检测服用阿奇霉素的COPD患者和服用安慰剂的COPD患者的痰中N-β-Pgp/Pgp水平和Pgp生成酶的活性，特别是基质金属蛋白酶和PE的活性。2.比较服用阿奇霉素的慢性阻塞性肺疾病患者痰与服用安慰剂的慢性阻塞性肺疾病患者痰体外从胶原蛋白生成N-α-Pgp/Pgp的能力。3.慢性阻塞性肺疾病患者诱导痰中N-Pgp/Pgp水平及PE活性与血清中N-Pgp/Pgp水平及活性的相关性。慢性阻塞性肺病现在是美国第四大死因，预计到2020年将成为第三大死因。这种疾病不仅给人们造成了巨大的经济负担，还给人们带来了许多痛苦。由于缺乏诊断生物标记物并在临床试验中用作终点，以及缺乏对疾病过程本身的基本了解，对COPD的理解导致成功的治疗方法受到阻碍。如果成功，目前的提案将产生对疾病过程的基本见解和COPD的新的特定生物标记物，以及建议新的治疗靶点。(摘要结束)

DESCRIPTION (provided by applicant): We describe a new pathway signaling neutrophil (PMN) influx and damage to the airways that may play a role in chronic obstructive pulmonary disease (COPD). Chemical or enzymatic breakdown of collagen releases a tripeptide, PGP, and an acetylated form (N-?-PGP) that are chemotactic for PMN. Prolonged airway exposure to this peptide causes alveolar enlargement and right ventricular hypertrophy. Further- more, PGP is found in the airways of animals exposed to aerosolized endotoxin (LPS) and markedly contributes to PMN influx. The enzymatic production of PGP is a stepwise process initially involving matrix metalloproteases (MMP)-8 and/or MMP-9 with prolyl endopeptidase (PE), a serine protease, catalyzing the final reaction. We have also found that PGP is present in bronchoalveolar lavage fluid (BALF) and/or sputum from most COPD patients but not controls or asthmatics. Sputum from COPD patients but not control individuals also contains all the enzymatic machinery necessary for the ex vivo generation of PGP from purified collagen and such PGP production can be blocked by MMP-8 or MMP-9 inhibitors or by a PE- specific inhibitors. The macrolide trial currently being conducted by the COPD Clinical Research Network (CRN) offers a unique opportunity to study the role of PGP in airway inflammation in COPD. Measurement of PGP and N-?-PGP in the cohort of COPD patients recruited for this trial will provide information which could otherwise only be acquired by another large-scale clinical trial. The current period of enrollment for this trial affords an important window of opportunity, belying the time-sensitive nature of this proposal. Measurement of MMP and PE levels and activity in sputum will provide new and important information on the generation of PGP in COPD and identify possible new therapeutic targets against airway inflammation in this disease. Importantly, macrolide antibiotics have been identified as negative transcriptional regulators for MMPs. This is proposed to underly a possible therapeutic activity in chronic lung diseases such as COPD. Finally, this trial will enable us to test this hypothesis in a large cohort of COPD patients, both taking azithromycin and controls, thereby providing a scientific basis for the activity of macrolides in COPD. Our underlying hypothesis is that levels of N-?-PGP/PGP and the activity of enzymes that generate them, specifically MMPs and PE, are lower in patients with COPD taking azithromycin than in COPD patients on placebo and that this reduction will correlate with improvement in clinical endpoints in these patients. Specific aims: 1. Measure levels of N-?-PGP/PGP and activity of PGP-generating enzymes, specifically MMP's and PE, in sputum of COPD patients taking azithromycin and in sputum of COPD patients taking placebo. 2. Compare the ability of sputum from COPD patients taking azithromycin to generate N-a- PGP/PGP ex vivo from collagen with sputum from COPD patients taking placebo. 3. Correlate levels of N-?-PGP/PGP and activity of PE in induced sputum with levels and activity in serum of COPD patients. COPD is now the fourth leading cause of death in the U.S. and is expected to be the third by 2020. This disease causes much human suffering as well as a large monetary burden. An understanding of COPD that leads to successful therapeutics has been hampered by a lack of biomarkers to diagnose and use as endpoints in clinical trials as well as a lack of a fundamental understanding of the disease process itself. If successful, the current proposal will yield fundamental insights into the disease process and a new and specific biomarker for COPD as well as suggesting new therapeutic targets. (End of Abstract)